# ZK Identity
###### Tags `Math`
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*Refer to 0xPARC and PSE*

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## General

Online identity systems enable complex online interactions and communities. However, the system still suffers from many weaknesses, most of which can be attributed to inherent limitations in the design of centralized identity systems.

E.g:

- **[pressure or interference](https://www.bbc.com/news/59338205)**
- **[technical attacks](https://www.upguard.com/breaches/facebook-user-data-leak)**
- **[Operators and users have unequal rights](https://blog.twitter.com/en_us/topics/company/2020/suspension)**

Decentralization and cryptographic mechanisms expand the design space of digital identity systems. They enable users of digital systems to generate credible claims of arbitrary complexity without relying on trusted parties.

Privacy is at the heart of trusted claims. Almost all identity systems rely on the notion of secret data to generate credible claims about identities. For example, passwords, social security numbers, private keys, credit card PINs, account recovery questions, etc. This data has to be kept private, and in traditional systems we have to delegate more power to central authorities - in such systems trusted claims of private data are almost impossible to verify.

For a long time, the development of cryptography and consensus has revolved around making credible claims without a central authority.

E.g:

- Digital signature schemes allow a series of messages to be signed using the same private key to generate credit claims
- Group signature schemes allow me to make more complex privacy-preserving claims about identity
- Signature aggregation, multi-signature, and threshold signature schemes allow me to make claims about group behavior, under various different resource constraints
- Consensus schemes and programmable smart contracts allow me to make credible and irreversible commitments to future actions

Around ZKID, there are four important components that still need to be continuously built:

- **ZKID Design Patterns**
- Abstraction
- Common identity claims
- Tools and standards
- Interfaces
- Devices and environments for prover
- **ZK Circuits for Cryptographic Identity Primitive**
- …
- **Developer Tools and Infrastructure**
- PLONK toolchains
- Higher-level DSLs
- Smarter development environments
- Build, testing, and deployment tools
- Common standards for intermediate representations
- Easier-to-use and more efficient compilers and provers
- (Pre-PLONK) Shared trusted setup infrastructure
- (Post-PLONK) Tools for working with SNARK recursion)
- **Auditing and Verification**
- Building a community of reviewers
- Establishing best practices for circuit engineering and review
- Manual proofs of correctness for circuit primitives
- Automated witness uniqueness verification

## ZKID apps